Longitudinally-oriented (e.g., monoaxial) toothbrushes may present difficulties in employing certain brushing methods. At least one of these methods includes positioning bristle tips of a brush at a particular angle to a surface to be cleaned, pressing the bristle tips against the gingiva, vibrating the bristles, and moving the bristles in small circular motions. This method, and similar methods, may present obstacles for individuals with lesser manual dexterity, such as the young, the elderly, or the physically challenged. Many users consequently resort to using a side-to-side scrubbing action, in which the bristle tips of the toothbrush do not penetrate in-between the teeth effectively or under the gumline. Such brushing techniques can cause loss of tooth enamel and damage to the gingiva or palatal tissues.
Although transversal toothbrushes can offer one or more advantages over monoaxial toothbrushes, cleaning the anterior lingual dental surfaces with some transversal toothbrushes may be difficult because the curve of the dental arch may cause the ends of the cleaning head to contact teeth adjacent to those to be cleaned. Previous remedies include providing a concave bristle profile, which renders the cleaning head unsuitable for cleaning concave dental surfaces; providing a double-ended transversal toothbrush with a convex-shaped cleaning head at one end and a concave-shaped head at the other, which may entail interrupting the brushing process to reverse the orientation of the toothbrush during brushing; and reducing the width of the cleaning head to a degree that may substantially reduce other advantages sought in the transversal configuration. The transversal toothbrush of EP0900033B, to Grivon and Hugon, has a curved handle and a brush head that can be manually adjusted between transversal and coaxial orientations to the longitudinal axis of the apparatus. The longitudinal toothbrush of U.S. Pat. No. 2,266,195, to Hallock, has a central head portion that is resilient and can move relative to the surrounding portion of the cleaning head to enable the entirety of the bristles to contact both convex and concave surfaces. The toothbrush of U.S. Pat. No. 2,232,269, to Reuben, has a pair of parallel necks one of which can be manually rotated so that its brush head is perpendicular to the other brush head. Cleaning apparatuses having a cleaning head longitudinal axis oriented substantially perpendicular to the longitudinal axis of the apparatus may have a cleaning head that is substantially rigid.